Improvement in slide-valves



wedgefshaped-projectionst UNITED- STATES PATENTI OFFICE.

,JOHNQ cooH'R'Am/on BROOKLYN, New YORK.

IMPROVEMENT In sLl DEfvALv'l-:SQ

' V' Sporidentico forming part of Letters Patent No. 47,932, (latedY May 3Q," '1. I

To all when@ itfmay concern:

' L Beit known that I, JOHN BfCocHnm. of

Brooklyn,I Kings'bounty, State of NewYork-- have invented a new and useful Improvement y "Figure 1 is avertical'longitudinal section of aslide-valve and itsiconnectionsjmade acoord'' ing to my invention-,j the section being `taken f This' invention consists in agnovel modeof operating slide-valves of -steam-engins, lso that it` may be' madeto cut oit' steam at any fdesiredpart of 'thestroke and be lso moved lwitlfa quick stroke, oneot'the features of the invention being the communication of the mo'- freef-is made'the' fulcriimzof the 4said. leverjf: A? is the steam-chest, .which jcontaihs: the

sli'df'fvalve B f f 1 a 'a' designate steam-ports, and fb an exhadstcylinder of theengneinthe u'sfu'alway. 'l' F is an eccentric, andEJa connecting-rod,

wvhich is adjustably connected to. the rock' l shaft arm D; The toe.'-

k .fof therLroCIt-shaft-is r 'connected tothe valvestV n' C; which .passes Vtop l or back of the slidervalvef to which v'its lower end is pivoted'. ``flll1lje-npperrfreeend of I theflver G isronndedythefrounded' part being .separated fromithe bodyr 'ofrthe leverlbya neck jwhose sides res; ectively cj 'in egpppositetlie the sides of the traveling V niios ee The edges of ftheprojections and 'vtheneclc of thelever, iGare thus fitted and arrangedfort'he purpose ofreducing the frictional contact of those parts -tothesmallest limits..` 1 "j Hisarod-.or shaft passing throughtne endsof the "steain-chest-and made` capableffof ire#x anding out from i 'volving inbearig's formed in said ends, but l Its place in thisexample is directly above theaxis of thevalve `having no motion. -endwise and of the valve-stem and parallel therewith.'

It has both a right-hand anda left-hand screvv-4 thread formed on it, each commencing near the middle of its length, and eachscrew-thread has'a traveling nut, c e-,whieh travel either to- -Ward each other or away from each other atllke speedvan'd at like times, when motion is glve'n to the rod Hthrou'gh its ljcranl'z I. The outward Vmovements of the nuts are limited by 'st opsf'depending from the top of the steami ch'est',. and through which the rodpasses, and

their movements toward each other arelimit yed by a xed nut `or stop, g, placedon therod=A Y at the middle of itslength, inthesame-vertif 'fx Y cal plane withthecenter ofthe 'eXhanstJpbft ,bu From .this lconstructionand arrangement l it will be seenthat Iproduce anadjustable cut-off of a very simple character, sincethe valve-stem lgives `motion to the valve through fthe leveIG; Yand since the upper endfof said lever,- which sthe third: or lthe a' ts fulcrum, (it being a lever of 'nto motion imparted-to the valve by th ipr t 'stem willbelg verned by thel distances of the center-fof thefcentral stop, g'- or,`-iniother1vords, fromeach other.V When Iclaim as Inewand desire to secure by Let tersPatent-l l l .11. The combination of the valvlelstem C with is movable, it is evidenti-,hat

ating movements ofthe v alve- Ahas'been moved toward theleft, as g. 1,'it i'snot'. again acted 'upon by r the eenen ric and its connections until thehead ,ofgthelever G has moved acrossthe distance which 'sermnfate-s the-nutsc, When ithas been i -fbrought'in contact with the nut on the right-` handlsida-the-further movement of the valvev stemirst begins to act upon the valve. I am thus' enabled to change the throw of thevalve and cutoff steam s'oonerjor laterin the stroke y bysmpl'y rotating the rod H and moving the'. nutse herto or farther away from-eachother.

The valve-stem can beattached to the lever.. Gat any part of its lengthand'in-such. away `asi not' tofbind the valve-stemwheieit passes through fthe .wali of the steam-chest. vThev valve-stem and the screw-rodlshouldpass` 'through stuffing-b0Xes',.where 'they enter the f sides of the 'steam-chest, so as to. prevent the 'escape -of steam. L 1.

nuts e e; operated as set forth, with the lever G, substantially as described.

JOHN 1;. CfmHlAN.

2. The combination of the rod H and its C. L. ToPLIFr. 

